transfusion reactions

Question 1

what causes an immediate hemolytic transfusion rxn?

Answer 1

ABO incompatible units
complement binding to C9 = intravascular hemolysis

Question 2

how long until an immediate hemolytic reaction and what are the symptoms

Answer 2

immediate 1-15 mins with fevers, chills, chest pain, and hemoglobinuria
progression: low BP, shortness of breath, nausea, burning along the vein, angioedema, back pain, anxiety, DIC, death

Question 3

what is the treatment of an immediate hemolytic

Answer 3

supportive care

Question 4

what are other rare non ABO causes of an immediate hemolytic reaction

Answer 4

pre formed antibody in the recipient
no antibody screen or antibody is too low frequency antigen (Cw, V, Kpa)
RBC unit is antigen positive (Kidd, Kell, Rh antibodies)

Question 5

how can we prevent an immediate hemolytic reaction?

Answer 5

CLERICAL CHECKS, ensure every product leaving the lab is AB compatible

Question 6

what is the cause of a febrile non hemolytic reaction?

Answer 6

soluble vasoactive cytokines in the product (often plt) from WBC breakdown
HLA antibodies in patient that react with donor wbc

Question 7

symptoms of a febrile non hemolytic

Answer 7

fever with or without chills

Question 8

treatment of a febrile non hemolytic reaction

Answer 8

acetaminophen, rule out other fever causing reactions
universal pre-storage leukoreduction has helped reduce febrile reductions

Question 9

what is the cause of a mild allergic (urticarial) reaction

Answer 9

mild allergic results from IgE antibodies in patient reacting with an allergen in the donor plasma (food, protein, preservative)

• antibodies bind mast cells which release granular contents (histamine) to give symptoms of urticarial (hives) and pruritis (itching)

have mild cardiac symptoms but BP is stable

Question 10

timing of a mild allergic reaction

Answer 10

1-45 mins start of transfusion

Question 11

treatment of mild allergic reaction

Answer 11

antihistamines - can transfuse slowly

Question 12

cause of a severe anaphylactic reaction

Answer 12

due to donor IgA antibodies (it is the antigen)
recipient is IgA deficient and makes anti-IgA from previous transfusions
Anti-Iga- IgA interactions leads to severe anaphylaxis
can be allergen in donor plasma but is rare (like peanuts)
IgE Mast cells degranulation

Question 13

timing of a sever anaphylactic reaction

Answer 13

within minutes of infusion (1-15 mins) can start mild allergic and progress

Question 14

symptoms of sever anaphylactic

Answer 14

• urticaria, pruritis, SOB, dyspnea, low BP, hypoxemia, GI
• smooth muscle contraction - GI, trachea, bronchi, bronchioles
• vasodilation - drop in blood pressure

Question 15

treatment of severe anaphylactic

Answer 15

epinephrine, antihistamines, corticosteroids, supportive therapy

Question 16

prevention of a severe anaphylactic reaction

Answer 16

request IgA deficient products
1/1000 people are IgA deficient
wash rbc/plt units
transfuse with caution

Question 17

cause of a bacteriogenic reaction

Answer 17

bacteria in blood product from
- normal skin flora from donor arm
- transient bacteremia in donor
- contamination of product during processing/ product manipulation
- improper storage temperature

Question 18

time of bacteriogenic reaction

Answer 18

minute - hours of toxins are present / high bacterial load in the bag several days if low microbial count - depends on patient’s immune status

Question 19

storage of blood products that can cause a bacteriogenic reaction

Answer 19

platelets that are store at 20-24 degrees
red cells that can grow psychrophiles (0-25): e coli, pseudomonas, yersinia enterocolitica

Question 20

symptoms of a bacteriogenic reaction

Answer 20

fever, chills, rigors, hypotension, flushing, clammy skin, tachycardia, DIC

Question 21

treatment of a bacteriogenic reaction

Answer 21

broad spectrum antibiotics (do blood cultures aerobic and anaerobic)
culture the donor products/ empty bag if available

Question 22

what is the cause of a delayed hemolytic reaction

Answer 22

antibody formation to non ABO antigens in donor blood (Rh, Kell, Kidd, Duffy, Ss)
antibodies bind donor cells and are removed by the liver and spleen (extravascular hemolysis)

Question 23

timing of a delayed hemolytic trxn

Answer 23

2-14 days post transfusion, usually due to secondary exposure

Question 24

products of a DH trxn

Answer 24

red blood cells

Question 25

symptoms of a DH trxn

Answer 25

fevers, chills, malaise, jaundice or no symptoms

Question 26

what is the treatment of a DH trxn

Answer 26

none!
monitor Hb, bilirubin, lactate dehydrogenase, and haptoglobin

Question 27

what are the hematological tests we can test

Answer 27

hemoglobin should be increased if transfused properly
hemoglobin is either decreased or increased
increased bilirubin means increase hemolysis
increased lactate dehydrogenase
decreased haptoglobin

Question 28

why is a positive DAT important post transfusion

Answer 28

a positive DAT is significant in a delayed hemolytic reaction

Question 29

what are some other rare causes of a pos DAT post transfusion

Answer 29

• transfusion of a passive antibody
• transfusion if IVIg that binds non specifically to rbs
• donor is DAT pos

Question 30

significance of the immune response curve

Answer 30

IgG antibody concentrations will increase after the secondary exposure and will bind to donor cells

Question 31

indicators of IVH

Answer 31

• visible hemolysis present
• hemoglobinuria
• decreased haptoglobin
• increased LD

Question 32

indicators of EVH

Answer 32

• increased bilirubin
• increased LD
• decreased haptoglobin
• decreased hemoglobin ( or Hb that fails to increase)

Question 33

transfusion reaction investigation procedure:

Answer 33

• clerical check (bedside, in lab - pretransfusion req, specimen, donor bag)
• review symptoms
• note product transfused
• time of transfusion to symtoms
• volume transfused
• check for visible hemolysis on post transfusion sample
• perform serological testing - ABO Rh, antibody screen, DAT, XM
• perform non serological testing - Hem or CHem

Question 34

a patient gets transfused and had an Abscr that was neg and XM that was neg, the post transfusion sample however has a neg Abscr, pos DAT, and a neg XM. what happened?

Answer 34

not enough antibody came up causing a neg Abscr
- happens closer to the beginning
eg. if anti-c present in the plasma -> will bind to donor cells in which less Ab left in plasma will be detected

Question 35

when doing a transfusion reaction these are the results of a screen, DAT and XM. what happened?
Abscr: pos
DAT: neg
XM: pos

Answer 35

starting the reaction all donor cells tagged are removed.

collection of this sample was done at a later time

Question 36

what is the delayed transfusion workup

Answer 36

• Ab ID if screen is positive
  -perform elution on DAT pos cells
• Ag type implicated donor segments
• do not Ag type patient if the have been transfused in the past 3 months
• update records
• serologically crossmatch with implicated donor units (should be pos)
• serologically crossmatch Ag neg donor for subsequent transfusions if XM is still valid (within 96 hours)

Question 37

what testing is done on these samples in a transfusion reaction:
pretransfusion sample
posttransfusion sample
donor segment

Answer 37

pre: clerical check, ABO Rh, Ab screen, serological crossmatch
post: clerical check, check hemolysis, ABO Rh, Ab screen, DAT, serological XM
donor: clerical check, ABO Rh, antigen type for Ab detected in pre or post sample